Free UUID Generator (v4)
Generate one or up to 100 version-4 UUIDs at once. Cryptographically random, runs entirely in your browser via the native crypto.randomUUID() API. Output in lowercase, uppercase, with braces, or with dashes stripped.
UUID v4 generated locally using crypto.randomUUID(). Browser-native, cryptographically random.
What is a UUID?
A UUID is a 128-bit identifier designed to be unique across all systems without central coordination. Probability of two randomly-generated v4 UUIDs colliding is so low it would take generating billions per second for a hundred years to expect even one collision.
Common uses include primary keys in databases, session IDs, request tracing identifiers, file names that must be guaranteed unique, and entity IDs in distributed systems.
Format reference
A standard UUID looks like 550e8400-e29b-41d4-a716-446655440000 — 32 hex digits broken into 5 groups by hyphens (8-4-4-4-12). The 13th digit always shows the version (here4), and the 17th encodes the variant.
Frequently asked questions
Related tools
- GUID Generator — alternative name, same thing
- API Key Generator
- Random String Generator
- Hash Generator


